The sky turned dark, then yellow, then blue balls began dropping out of the sky. Not the start of a science fiction film but Steve Hornsby's account of a strange happening in his back yard in Dorset.

Hornsby is trying to find out what the transparent, marble-sized objects that peppered his home in Bournemouth could be.

The 61-year-old said he was walking to his garage at around 4.10pm on Thursday when what he thought was an ordinary storm hit. He took shelter but once the downpour had finished he noticed the lawn was dotted with blue balls.

Hornsby, an aircraft engineer, said: "I was just about to pop into the garage to get some logs for the fire when the sky went very dark and then a strange yellow colour. There was then a short, sharp hail storm that lasted for about 20 seconds.

"I rushed to stand by the wall out of the way and it was all over very quickly. I had seen the hail come down and it looked like rock salt. But then I spotted something on the lawn and it looked like broken glass.

"But then I put my foot on it and it disappeared and I thought it was strange. Then I looked around and there were lots of others. They were definitely not there before the storm.